Solid-Phase Debundling of Single-Walled Carbon Nanotubes for the "Stock Solid" Delivery of Concentrated Nanotube Dispersions

Debundling of single-walled carbon nanotubes (SWNTs) has been mostly limited to liquid-phase exfoliation. Since the SWNTs in dispersion are prone to aggregate and precipitate gradually during their storage, a solid-phase method that provides debundled SWNTs as "stock solid" is highly required. Herein, we report on a solution to this issue, which is based on solid-phase ball milling. The milled solid, composed of debundled SWNTs and surfactant, can be stored as "stock solid" and is readily dispersed in water just by shaking with hand, giving concentrated SWNTs dispersion (up to 1.16 mg/mL) with yield up to 60% after centrifugation.